Building Multi-Container Applications using Podman Quadlets

#podman #wordpress #tutorial #container

A perfect practical application for Quadlets is deploying a WordPress stack.
This illustrates how multiple containers can communicate with each other.

1. Common Network (wp.network)
2. The mariadb Container (mariadb.container)
3. The WordPress Container (wordpress.container)
4. Key Adjustments Made
5. How to Start It

1. Common Network (wp.network)

Create a quadlet network file at ~/.config/containers/systemd/wp.network

[|=| raspi in ~/pods/wordpress ]$ cat ~/.config/containers/systemd/wp.network
[Network]
Label=app=wordpress

[|=| raspi in ~/pods/wordpress ]$

2. The mariadb Container (mariadb.container)

Create a quadlet container file at ~/.config/containers/systemd/

[|=| raspi in ~/pods/wordpress ]$ cat ~/.config/containers/systemd/mariadb.container
[Unit]
Description=MariaDB WordPress Database

[Container]
ContainerName=mariadb
Image=docker.io/library/mariadb:latest
# Quadlet likes environment variables on one line or using a separate env file
Environment=MYSQL_ROOT_PASSWORD=wordpress MYSQL_DATABASE=wordpress MYSQL_USER=wordpress MYSQL_PASSWORD=wordpress
Exec=--default-authentication-plugin=mysql_native_password
Volume=/home/solifugo/pods/wordpress/db_data:/var/lib/mysql
Network=wp.network
PublishPort=3306:3306

[Service]
Restart=always

[Install]
WantedBy=wordpress.service multi-user.target default.target

[|=| raspi in ~/pods/wordpress ]$

3. The WordPress Container (wordpress.container)

Create a quadlet container file at ~/.config/containers/systemd/

[|=| raspi in ~/pods/wordpress ]$ cat ~/.config/containers/systemd/wordpress.container
[Unit]
Description=WordPress Web Server
After=mariadb.service

[Container]
Image=docker.io/library/wordpress:latest
Environment=WORDPRESS_DB_HOST=mariadb:3306 WORDPRESS_DB_USER=wordpress WORDPRESS_DB_PASSWORD=wordpress WORDPRESS_DB_NAME=wordpress
Volume=/home/solifugo/pods/wordpress/wp-content:/var/www/html/wp-content
PublishPort=8042:80
Network=wp.network

[Service]
Restart=always

[Install]
WantedBy=multi-user.target default.target

[|=| raspi in ~/pods/wordpress ]$

4. Key Adjustments Made

Networking: In Podman, containers in the same default network can talk to each other using their filenames as hostnames.
I set WORDPRESS_DB_HOST=mariadb to match the mariadb.container filename.
Dependencies: The After=mariadb.service line in the WordPress file ensures the database attempts to start before the web server.

5. How to Start It

Once the files are in ~/.config/containers/systemd/, run the following commands:

Reload systemd to generate the services and start the service

[|=| raspi in ~/pods/wordpress ]$ systemctl --user daemon-reload

[|=| raspi in ~/pods/wordpress ]$ systemctl --user list-unit-files |grep -E 'word|mari'
mariadb.service                                generated -
wordpress.service                              generated -

[|=| raspi in ~/pods/wordpress ]$

[|=| raspi in ~/pods/wordpress ]$ systemctl --user start wordpress.service

[|=| raspi in ~/pods/wordpress ]$ systemctl --user status wordpress.service
● wordpress.service - WordPress Web Server
     Loaded: loaded (/home/solifugo/.config/containers/systemd/wordpress.container; generated)
     Active: active (running) since Fri 2026-02-13 12:30:18 GMT; 3 days ago
 Invocation: b544331ed44d4d1f8092e71265ab7783
   Main PID: 1511243 (conmon)
      Tasks: 23 (limit: 8750)
        CPU: 20.699s
[...]
[|=| raspi in ~/pods/wordpress ]$